This invention relates generally to hinges, and more particularly to low-cost, lightweight hinges of the self-latching type. An example of the application of such a hinge is the access door or cover for a room air conditioner unit. Such a cover is used on many types of room air conditioners to cover the control panel for appearance purposes, and is easily openable to allow access to the unit controls on the control panel behind the door. Such a hinge need be of only lightweight construction, since the cover is generally formed of a plastic material as often is the front panel or frame of the air conditioner to which the cover is mounted. While such covers may be provided with a detent to hold them in the closed position, it is more desirable to be able to use a hinge of the self-latching type, which provides a biasing force tending to move the cover to a tightly closed position when it is closed to within a certain small angle of the fully closed position.
Such hinges shuld be of a low-cost construction and allow quick assembly during production, yet they should be easy to replace in the field if they should become broken.
One prior hinge arrangement for air conditioner doors is shown in U.S. Pat. No. 4,065,027, in which most of the hinge structure is formed as complementary portions on both the frame and the cover, with the rotation or pivoting action occurring about a hinge pin that is snapped in place on the cover portion and retained on the frame or panel at the upper and lower ends of the hinge pin. This construction requires complicated tooling on both the panel or frame and the door, and fails to provide the self-latching or detent feature to hold the access door in the closed position.
Hinges which provide a self-latching action are well known in a somewhat heavier duty form used for doors for kitchen cabinets and the like. Such hinges, such as shown in U.S. Pat. Nos. 3,381,332 and 3,381,333, are of more complicated and heavier duty construction required to support doors weighing several pounds each, as compared to an air conditioner access door which, typically, may weigh ony several ounces and be considerably smaller in size.